We study semiconductor hyperbolic metamaterials (SHMs) at the quantum limit experimentally using spectroscopic ellipsometry as well as theoretically using a new microscopic theory. The theory is a combination of microscopic density matrix approach for the material response and Green's function approach for the propagating electric field. Our approach predicts absorptivity of the full multilayer system and for the first time allows the prediction of in-plane and out-of-plane dielectric functions for every individual layer constructing the SHM as well as effective dielectric functions that can be used to describe a homogenized SHM.
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http://dx.doi.org/10.1038/s41598-018-35099-8 | DOI Listing |
Adv Mater
December 2024
Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, 560064, India.
Metal/semiconductor superlattices represent a fascinating frontier in materials science and nanotechnology, where alternating layers of metals and semiconductors are precisely engineered at the atomic and nano-scales. Traditionally, epitaxial metal/semiconductor superlattice growth requires constituent materials from the same family, exhibiting identical structural symmetry and low lattice mismatch. Here, beyond this conventional constraint, a novel class of epitaxial lattice-matched metal/semiconductor superlattices is introduced that utilizes refractory hexagonal elemental transition metals and wide-bandgap III-nitride semiconductors.
View Article and Find Full Text PDFHeliyon
March 2024
School of Mechanical and Electrical Engineering, Chizhou University, Chizhou 247000, Anhui, China.
Based on the usual Wigner-Weyl transformation theory we find that the Wigner hyperbolic rotation in phase space will map onto fractional squeezing operator in Hilbert space. The merit of Weyl ordering and the coherent state representation of Fresnel operator is used in our derivation.
View Article and Find Full Text PDFNat Commun
January 2024
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences & School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190, China.
Anisotropic materials with oppositely signed dielectric tensors support hyperbolic polaritons, displaying enhanced electromagnetic localization and directional energy flow. However, the most reported hyperbolic phonon polaritons are difficult to apply for active electro-optical modulations and optoelectronic devices. Here, we report a dynamic topological plasmonic dispersion transition in black phosphorus via photo-induced carrier injection, i.
View Article and Find Full Text PDFNat Commun
December 2023
Department of Physics, Columbia University, New York, NY, USA.
Exciton polaritons are quasiparticles of photons coupled strongly to bound electron-hole pairs, manifesting as an anti-crossing light dispersion near an exciton resonance. Highly anisotropic semiconductors with opposite-signed permittivities along different crystal axes are predicted to host exotic modes inside the anti-crossing called hyperbolic exciton polaritons (HEPs), which confine light subdiffractionally with enhanced density of states. Here, we show observational evidence of steady-state HEPs in the van der Waals magnet chromium sulfide bromide (CrSBr) using a cryogenic near-infrared near-field microscope.
View Article and Find Full Text PDFNat Commun
December 2023
Department of Mechanical Engineering, Vanderbilt University, Nashville, TN, 37240, USA.
Hyperbolic phonon polaritons (HPhPs) can be supported in materials where the real parts of their permittivities along different directions are opposite in sign. HPhPs offer confinements of long-wavelength light to deeply subdiffractional scales, while the evanescent field allows for interactions with substrates, enabling the tuning of HPhPs by altering the underlying materials. Yet, conventionally used noble metal and dielectric substrates restrict the tunability of this approach.
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